IRVINE — Beating UC Santa Barbara for the first time in Coach Paula Weishoff's four-year tenure was no small feat for the UC Irvine women's volleyball team.

The Anteaters shrugged off their propensity to shrink in the Big West Conference caldron Friday by seizing their chance to, in the words of UCI coaches, "Be big!."

The result was a 25-14, 19-25, 25-23, 28-26 conference-opening triumph that could shape the remainder of the Anteaters' season.

"In the past, if we had a tough preseason, this match was the defining moment of our season," Weishoff said of the conference opener, which her squad had lost its first three seasons, including five-set road setbacks against Pacific and UCSB, as well as a five-set home loss to Cal Poly San Luis Obispo.

"With anything you do, you have to have passion," Weishoff said. "At times, we got a little scared in the preseason and we backed off. One of our things is, we need to be big. We've got to step up. Because what can you do, fail? What does that do to us? We would step into a situation and not succeed, and then back down completely."

It was the Gauchos (7-8), who have made 26 NCAA Tournament appearances in the previous 37 seasons under Coach Kathy Gregory, and had a 65-8 series lead over UCI coming in, who were forced onto their heels Friday.

UCI (6-8), trying to avoid its fourth two-match losing streak of the season, scored the first three points of the contest and proceeded to build its lead until the end of the opening set.

UCI hit .361 as a team in Game 1, while posting a 5-0 advantage in team blocks to help hold the Gauchos to a woeful .070 hitting percentage. Other than junior Leah Sully, who had six kills in the opening set, the seven other Gauchos attackers hit zero or negative.

"The past week, we needed to step back and look at what we can control and the one thing we weren't really doing was celebrating," said UCI 6-foot-2 freshman outside hitter Marisa Bubica. "Everything we worked on this week, you could see it on the court. And I feel like we made a conscious effort to celebrate."

The 'Eaters wound up celebrating plenty after Game 4, despite seeing an 18-15 lead turn into a pair of set points for the visitors.

But junior middle blocker Shannon Fleming teamed with senior setter Marissa Alvarez for a stuff block that forged a 24-24 deadlock.

After UCSB earned a 25-24 edge, Bubica, who had 12 kills, second-best for UCI behind junior outside hitter Ally Squires' 15, connected for a kill to force another deadlock.

A hitting error gave UCI the first of its two match points, but UCSB junior opposite Katey Thompson, a Newport Harbor High product, posted her match-best 20th kill to create another deadlock.

Bubica drove a kill off the block to create another match point and Alvarez, who had 47 assists and 13 digs, produced her first ace to spark the final UCI celebration.

Fleming had 12 kills and four block assists, while Ella Rosenfeld, a 6-3 freshman middle, chipped in six kills (a .500 hitting percentage) and a match-best eight block assists to help UCI finish with a 12-5 advantage in team blocks.

Senior libero Kristin Winkler had 26 digs and helped UCI post a .975 percentage on service receive, 43 points better than the visitors.

"We were all super pumped up to play this first conference match," Squires said. "When we celebrate [each point] it gives us confidence and it brings us together as a team every time."

Britton Taylor, a junior middle blocker for UCSB who played at Corona del Mar High, had 13 kills, a team-best three block assists, and hit .417, tops among Gauchos regulars.

UCI never led in Game 2, but prevailed in a seesaw third game in which the score was tied 10 times.

Sydney Wright (eight kills and six block assists), was also integral for UCI.

The 'Eaters play host to Cal Poly on Saturday at 7 p.m.

barry.faulkner@latimes.com

Twitter: @BarryFaulkner5